/*
 * Copyright 2001-2005 (C) MetaStuff, Ltd. All Rights Reserved.
 *
 * This software is open source.
 * See the bottom of this file for the licence.
 */

package org.dom4j.rule;

import java.util.HashMap;
import java.util.Map;

import org.dom4j.Attribute;
import org.dom4j.Document;
import org.dom4j.Element;
import org.dom4j.Node;

/**
 * <p> <code>Mode</code> manages a number of RuleSet instances for the mode in
 * a stylesheet. It is responsible for finding the correct rule for a given
 * DOM4J Node using the XSLT processing model uses the smallest possible RuleSet
 * to reduce the number of Rule evaluations. </p>
 * 
 * @author <a href="mailto:james.strachan@metastuff.com">James Strachan </a>
 * @version $Revision: 1.2 $
 */
public class Mode
{
   private RuleSet[] ruleSets = new RuleSet[Pattern.NUMBER_OF_TYPES];

   /** Map of exact (local) element names to RuleSet instances */
   private Map elementNameRuleSets;

   /** Map of exact (local) attribute names to RuleSet instances */
   private Map attributeNameRuleSets;

   public Mode()
   {
   }

   /**
    * Runs the actions associated with the given node
    * 
    * @param node DOCUMENT ME!
    * 
    * @throws Exception DOCUMENT ME!
    */
   public void fireRule(Node node) throws Exception
   {
      if(node != null)
      {
         Rule rule = getMatchingRule(node);

         if(rule != null)
         {
            Action action = rule.getAction();

            if(action != null)
            {
               action.run(node);
            }
         }
      }
   }

   public void applyTemplates(Element element) throws Exception
   {
      for(int i = 0, size = element.attributeCount(); i < size; i++)
      {
         Attribute attribute = element.attribute(i);
         fireRule(attribute);
      }

      for(int i = 0, size = element.nodeCount(); i < size; i++)
      {
         Node node = element.node(i);
         fireRule(node);
      }
   }

   public void applyTemplates(Document document) throws Exception
   {
      for(int i = 0, size = document.nodeCount(); i < size; i++)
      {
         Node node = document.node(i);
         fireRule(node);
      }
   }

   public void addRule(Rule rule)
   {
      int matchType = rule.getMatchType();
      String name = rule.getMatchesNodeName();

      if(name != null)
      {
         if(matchType == Node.ELEMENT_NODE)
         {
            elementNameRuleSets = addToNameMap(elementNameRuleSets, name, rule);
         }
         else if(matchType == Node.ATTRIBUTE_NODE)
         {
            attributeNameRuleSets =
               addToNameMap(attributeNameRuleSets, name, rule);
         }
      }

      if(matchType >= Pattern.NUMBER_OF_TYPES)
      {
         matchType = Pattern.ANY_NODE;
      }

      if(matchType == Pattern.ANY_NODE)
      {
         // add rule to all other RuleSets if they exist
         for(int i = 1, size = ruleSets.length; i < size; i++)
         {
            RuleSet ruleSet = ruleSets[i];

            if(ruleSet != null)
            {
               ruleSet.addRule(rule);
            }
         }
      }

      getRuleSet(matchType).addRule(rule);
   }

   public void removeRule(Rule rule)
   {
      int matchType = rule.getMatchType();
      String name = rule.getMatchesNodeName();

      if(name != null)
      {
         if(matchType == Node.ELEMENT_NODE)
         {
            removeFromNameMap(elementNameRuleSets, name, rule);
         }
         else if(matchType == Node.ATTRIBUTE_NODE)
         {
            removeFromNameMap(attributeNameRuleSets, name, rule);
         }
      }

      if(matchType >= Pattern.NUMBER_OF_TYPES)
      {
         matchType = Pattern.ANY_NODE;
      }

      getRuleSet(matchType).removeRule(rule);

      if(matchType != Pattern.ANY_NODE)
      {
         getRuleSet(Pattern.ANY_NODE).removeRule(rule);
      }
   }

   /**
    * Performs an XSLT processing model match for the rule which matches the
    * given Node the best.
    * 
    * @param node is the DOM4J Node to match against
    * 
    * @return the matching Rule or no rule if none matched
    */
   public Rule getMatchingRule(Node node)
   {
      int matchType = node.getNodeType();

      if(matchType == Node.ELEMENT_NODE)
      {
         if(elementNameRuleSets != null)
         {
            String name = node.getName();
            RuleSet ruleSet = (RuleSet) elementNameRuleSets.get(name);

            if(ruleSet != null)
            {
               Rule answer = ruleSet.getMatchingRule(node);

               if(answer != null)
               {
                  return answer;
               }
            }
         }
      }
      else if(matchType == Node.ATTRIBUTE_NODE)
      {
         if(attributeNameRuleSets != null)
         {
            String name = node.getName();
            RuleSet ruleSet = (RuleSet) attributeNameRuleSets.get(name);

            if(ruleSet != null)
            {
               Rule answer = ruleSet.getMatchingRule(node);

               if(answer != null)
               {
                  return answer;
               }
            }
         }
      }

      if((matchType < 0) || (matchType >= ruleSets.length))
      {
         matchType = Pattern.ANY_NODE;
      }

      Rule answer = null;
      RuleSet ruleSet = ruleSets[matchType];

      if(ruleSet != null)
      {
         // try rules that match this kind of node first
         answer = ruleSet.getMatchingRule(node);
      }

      if((answer == null) && (matchType != Pattern.ANY_NODE))
      {
         // try general rules that match any kind of node
         ruleSet = ruleSets[Pattern.ANY_NODE];

         if(ruleSet != null)
         {
            answer = ruleSet.getMatchingRule(node);
         }
      }

      return answer;
   }

   /**
    * DOCUMENT ME!
    * 
    * @param matchType DOCUMENT ME!
    * 
    * @return the RuleSet for the given matching type. This method will never
    *         return null, a new instance will be created.
    */
   protected RuleSet getRuleSet(int matchType)
   {
      RuleSet ruleSet = ruleSets[matchType];

      if(ruleSet == null)
      {
         ruleSet = new RuleSet();
         ruleSets[matchType] = ruleSet;

         // add the patterns that match any node
         if(matchType != Pattern.ANY_NODE)
         {
            RuleSet allRules = ruleSets[Pattern.ANY_NODE];

            if(allRules != null)
            {
               ruleSet.addAll(allRules);
            }
         }
      }

      return ruleSet;
   }

   /**
    * Adds the Rule to a RuleSet for the given name.
    * 
    * @param map DOCUMENT ME!
    * @param name DOCUMENT ME!
    * @param rule DOCUMENT ME!
    * 
    * @return the Map (which will be created if the given map was null
    */
   protected Map addToNameMap(Map map, String name, Rule rule)
   {
      if(map == null)
      {
         map = new HashMap();
      }

      RuleSet ruleSet = (RuleSet) map.get(name);

      if(ruleSet == null)
      {
         ruleSet = new RuleSet();
         map.put(name, ruleSet);
      }

      ruleSet.addRule(rule);

      return map;
   }

   protected void removeFromNameMap(Map map, String name, Rule rule)
   {
      if(map != null)
      {
         RuleSet ruleSet = (RuleSet) map.get(name);

         if(ruleSet != null)
         {
            ruleSet.removeRule(rule);
         }
      }
   }
}

/*
 * Redistribution and use of this software and associated documentation
 * ("Software"), with or without modification, are permitted provided that the
 * following conditions are met:
 * 
 * 1. Redistributions of source code must retain copyright statements and
 * notices. Redistributions must also contain a copy of this document.
 * 
 * 2. Redistributions in binary form must reproduce the above copyright notice,
 * this list of conditions and the following disclaimer in the documentation
 * and/or other materials provided with the distribution.
 * 
 * 3. The name "DOM4J" must not be used to endorse or promote products derived
 * from this Software without prior written permission of MetaStuff, Ltd. For
 * written permission, please contact dom4j-info@metastuff.com.
 * 
 * 4. Products derived from this Software may not be called "DOM4J" nor may
 * "DOM4J" appear in their names without prior written permission of MetaStuff,
 * Ltd. DOM4J is a registered trademark of MetaStuff, Ltd.
 * 
 * 5. Due credit should be given to the DOM4J Project - http://www.dom4j.org
 * 
 * THIS SOFTWARE IS PROVIDED BY METASTUFF, LTD. AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL METASTUFF, LTD. OR ITS CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 * 
 * Copyright 2001-2005 (C) MetaStuff, Ltd. All Rights Reserved.
 */
